Potato pieces, i.e. slices, chips, potato skins and cubes are prepared by frying in oil. During this frying process, water is lost from the potato and oil is absorbed. Conventionally fried potato chips can absorb up to 35% fat or oil. French fries usually absorb up to about 16% fat or oil. Therefore, a method which could lower the amount of oil absorbed by the potato pieces without affecting fried flavor and texture is highly desirable.
It has been discovered that the addition of silica particles to an oil or to the surface of the potato, will decrease the amount of fat absorbed by the potato by 10% to 25%. This decrease in the absorption of fat can lower the fat content of 1/4" french fries from about 16% to about 12%, making a healthier food.
Silica materials have been added to oils to increase their viscosity. See, for example, U.S. Pat. No. 4,605,563 to Heine et al (1986). The viscosity of oils is increased by adding from 1 to 10% of a high melting glyceride and from 2 to 10% of a highly dispersed pyrogenic silica having submicron particles.
In CRC Critical Reviews in Food Science and Nutrition, Vilotta et al, "Food Applications and the Toxicological and Nutritional Implications of Amorphous Silicon Dioxide", 23 (4), (289-321) the food uses of silicas are described. In addition to their use as suspending agents or thickening/thixotropic agents in oils, they are added to foods for anti-caking and dispersion. See for example U.S. Pat. No. 4,375,483 issued to Shuford et al (salt is dispersed in an oil), U.S. Pat. No. 4,834,991 issued to Porcello et al (1989) (filler cream), U.S. Pat. No. 4,652,458 issued to Frost et al (1987) (lipid composition), U.S. Pat. No. 4,103,038 issued to Roberts (1978) (synthetic egg), and U.S. Pat. No. 3,669,681 issued to Shoaf et al (1972) (fat for toaster pastry).
Silica has also been used to remove impurities from oil.
Silicas have also been used to make coatings. For example, U.S. Pat. No. 4,016,337 issued to Hsu (1977) discloses a water-dispersible composition consisting of co-agglomerates of finely-divided silicon particles of a non-dispersible material (corn starch) and a silicon dioxide flowing agent. These co-agglomerates have a thin coating of an emulsion of an edible fat and glycerine.
Coatings have also been used to lower the fat content of a french fry. U.S. Pat. No. 4,917,908 issued to Prosise (1990) describes a method wherein the potato slice is coated with polyvinylpyrrolidine (PVP) before it is fried. The PVP makes a barrier around the fry keeping it from absorbing oil.
While silica has been previously added to oils, it is surprising that the addition of less than 2% of this material to a frying fat or oil affects the oil or fat levels in a fried potato product.
Accordingly, it is an object of this invention to produce a french fry or fried potato product having a 10% to 25% lower fat content than the same potato fried in oil without silica.
It is also an object of this invention to provide a method for lowering the fat content of french fries and other fried potato products by coating the potato piece with silica. These and other objects will be obvious from the description herein.
All percentages are by weight unless otherwise noted.